Internal-combustion engine



June 16, 1925. 1,542,111 M. TIBBETTS INTERNAL COMBUSTION ENGINE FiledJan. 7, 1922 2 Sheets-Sheet 1 June .1 6, 1925. 1,542,l 1 l M. TIBBETTSINTERNAL COMBUSTION ENGINE Fild Jan. 7. 1922 2 Sheets-Sheet 2 INVENTOR;

Patented June 16, 1925.

UNITED STATES 1,542,111 PATENT OFFICE."

MILTON TIBBETTS, OF DETROIT, MICHIGAN, ASSIGiNOR TO PACKARD MOTOR CARCOM- IANY, OF DETROIT, MICHIGAN,

A CORPORATION OF MICHIGAN.

INTERNAL-COMBUSTION ENGINE.

.Application filed January 7, 1922. Serial No. 527,535.

1 '0 all whom it may concern Be it known that I, Murrow 'l.ienu'i'rs, acitizen of the United States, and resident of Detroit, Wayne County,State of Michigan, have invented certain new and useful Improvements inInternal-(lombustion Engines, of which the following isa specification.

This invention relates to internal combustion engines and articular-1yto means for controlling the mixture supplied thereto.

In connection with internal combustion engines, particularly as used inmotor vehicles, it is found desirable in starting to increase therichness of the mixture supplied to the engine, and particularly is thistrue in cold weather. At'some times it is even necessary to choke offpractically all of the air from the carburetor to permit raw gasoline toenter the cylinders or to be supplied to the intake pipe for producing.a very rich mixture to get the initial explosion.

Various forms and types of carburetors have been designed for producingthis richness of mixture for starting purposes. In some of them thegasoline nozzle is enlarged or the level is changed and in some the airvalves are closed or the air valve so springs have their tensionincreased, and in some cases both of these'things are done. In many such.carburetors the air is practically'all choked off for producing anunusual pull on the gasoline as the engine is turned over by itsstarting motor.

All such carburetors have a normal or most desirable setting of thesevarious valves and other devices and the parts are designed to bereturned to their normal positions as soon as the motor warms upsufliciently to accept and operate upon the leaner mixture which thenormal setting produces. Usually the return to normal setting isobtained by manual operation of the control device though in someinstances the parts have been automatically returned by the use ofthermostats or similar devices.

The present invention has for its salient object the provision of meansfor returning the carburetor to its normal setting in substantial accordwith'the Warming up of the motor while at the same time permittingmanual operation of the controls.

Another object of the invention is to provide means for returning thecarburetor to 18 will be opened to increase the volume 110 its normal.setting in accordancewith the heatin up of the motor, but at all eventsreturning the carburetor to its original setting whether the motor heatsu or not.

Other objects of the inventlon will appear from the followingdescription taken in. connection with the drawings, which form a part ofthis specification, and in which: F g. 1 1s aside elevatlon of a portionof an internal combustion engine with the present invention arrangedthereon, and

with parts of the carburetor and control devices 1n section;

Fig. 2 is somewhat similar to Fig. 1 with the parts in abnormalposition;

Fig. 3 is an enlarged plan view of part of the control mechanism shownin Figs. 1 and 2;

Fig. 4 is an enlarged detail view oil?v the spring return device anddash pot, the latter being shown in section;

Fig. 5 is a sectional view of the dash pot with the parts in anotherposition;

Figs. 6, 7 and 8 are cross sections on the lines 66, 77 and 8- -8respectively of Fig. 4; and

Fig. 9- is' a sectional view illustrating a slightly different form ofthe invention.

Referring to the drawings, 10 is an internal combustion engine having acarburetor 11 connected thereto. An exhaust pipe 12 is shown asextending along one si e of the engine. Such an en ine may be mounted ina motor vehicle an is usually arranged forward of a dash 13 which is inreach of the operator.

The carburetor 11 may comprise any desirable form of mixture devlce inwhich means are provided for var ing the mixture. As shown there is auel nozzle 14:, a main air intake 15, controlled by a butterfly valve16, an auxiliar air intake 17 controlled by a valve 18, an a sprlng 19adapted to yieldingly retain the valve 18 on its seat. A sleeve 20operates on the stem of the valve 18 to adjust the tension of thespringli). In Fig. 1 the parts are shown in normal position with thebutterfly valve 16 wide open and the spring 19 set to its minimumposition so that the valve 18 is very lightly seated. In this Way thelighter. loads will draw air through the main intake only but as thesuction increases the valve air is admitted to it.

of air and thus keep the proportions prac-- tically the same throughoutthe operation of the carburetor. The tension of the spring 19 may beincreased to thereby lessen the proportion of air and hence cause aricher mixture, by raising the sleeve 20. A cam 21, shown in dottedlines in Fig. 1 and in full lines in Fig. 2, is provided for thispurpose. It is pivoted at 22 and is operated by an arm 23. A second arm24 has a pin and slot connection 25 with a rod 26 connecting with an arm27 on the spring opened butterfly valve 16. A spring 28 is the means forretaining this valve 16 yieldingly in its open position as it is shownin Fig. 1..

In Fig. 1 the abm'e referred to parts of the carburetor are shown intheir normal position or as set for running after the motor has heatedup. The valve 16 is wide openand the spring 19 is set at its minimumtension. In Fig.2 the parts are in the other extreme position with thecarburetor choked to its fullest extent so that practically no Of coursethere is some air leakage past the valves, the valve 16 in particularbeing usually formed with a small leakage port, and in consequence astream of liquid fuel is drawn from the nozzle 14 by the action of theengine pistons as the engine is turned over by its starting motor. Inthis choked position of the parts of the carburetor the "alve 16 abutsagainst the lower end of the stem of the valve 18,

as shown in Fig. 2, so that the latter'valve is positively retained onits seat. It will be seen that by reason of the pin and slot connection25 between the cam 21 and the valve 16 the cam moves throughout agreater part of its range without changing the position of the valve 16.However, when the pin reaches the end of the slot the further movementof the cam 21 in tightening the spring 19 causes a quick closing of thechoke valve nected by a rod to the arm 23 of the mechanism for varyingthe carburetor mixture. device is provided for yieldingly orfrictionally retaining the rod 29 in its adjusted position, which deviceis sufficient to resist the tension of the carburetor spring 19 againstthe cam 21 tending to return the latter to its normal position. Such aretaining device is illustrated in Fig. 1 and is indicated at 36 asmounted on the dash 13. It comprises a casting secured to the dash asshown and the rod passes through it and is engaged by a spring pressedball 37 which enters serrations 38 in the rod. It will be understoodthat the tension on the spring pressed ball 37 is just suflicient toretain the rod 29 in its set position from which it may be easily movedby the operator.

This means for moving the carburetor mixture means from itsnormalposition is adapted to be returned to normal position by a spring anddash pot device 39, shown in several of the figures. This device isshown in detail in Figs. 4 to 8 inclusive and in the form illustrated itcomprises a cylinder 40 having ears 41 by which it is secured to theexhaust pipe 12 as by bolts 42. The lower end of the cylinder is closedand at its upper end it is provided with a cap 43 threaded onto it. Apiston 44 operates in the cylinder and a piston rod 45 extends from thepiston upwardly through the cap 43, the upper end of the. rod 45 beingformed with a flange 46. A coil spring 47 is arranged between the pistonand the cap 43 to yieldingly press the piston, and with it the pistonrod 45-, towards the bottom of the cylinder. The piston 44 is formedwith a series of openings or ports 48 therethrough and the cylinder isintended to con- -tain oil or other fluid which may pass through theports 48 from one part of the cylinder to the other as the piston movesin it. A valve 49 yieldingly pressed to its seat by a spring 50 closesall of the ports 48 and thus prevents passage of the fluid from thelower to the upper part of the cylinder except through a leakage port 51formed in the valve or elsewhere as desired. The tension of the spring50 is such that the valve 49 will readily open as the piston is movednpwardl to thus permit free passage of the flui from the upper to thelower part of the cylinder. Thus there is little or no retarding actionof the piston as it moves upwardly. The cylinder40 is also formed with aby-pass 52, the ports 53 and 54 of which are so arranged that theby-pass becomes operative and permits free movement of the piston ineither direction shortly before the piston reaches the upper end of itstravel. The operation of the bypass is shown particularly in Fig. 5. InFig. 4 the by-pass is inoperative because the piston has passed downover the port 53.

The above described piston and dash pot device is connected to the meansfor operating the mixture varying device of the.

carburetor by means of an arm 55 which extends ;trom the bell cranklever 31. The outer end of the arm 55 is in the form of a yoke 56 theparts of which pass on both sides of the piston rod 45 and operateagainst the under side of the flange 46.

Thus when. the rod 29 is moved by the o erator towards the left in Fig. 1. the bell crank lever 31, is rocked on its pivot and the arm 55moves upwardly and carries with it the piston rod 45 and the piston 44,against the action of the spring 47. In thus moving upwardlythe piston44 causes the valve 49 to open against its spring 50, to permit the freepassage of the oil from the upper to the lower part of the cylinder.There is very little resistance to this movement. \Vhen the rod 29 isthen released by the operator the spring 47 forces the piston downwardlyand carries with it the arm] 55 and thus rocks the bell crank lever 31.This movement, of course, returns the carburetor mixture device tonormal position. it th oil in the cylinder is thin this downwardmovement of the piston is comparatively rapid and the parts are at oncereturned to their normal settingv If, however, the oil in the cylinderis thick, as it is when it is cold, the downward movement of the pistonis greatly retarded due-"to the fact that the oil must pass through theport 51 and the spring action therefore is'sluggish and the parts returnvery slowly to their normal setting.

\Vhen the mechanism above described is used on an engine as shown theretarding action is very noticeable when the motor is cold but asthemotor heats up the exhaust pipe transfers heat to the cylinder and thusthe oil in the cylinder is warmed and becomes thin thus permitting thepiston to return to its normal position. The piston can only be movedupwardly again by the operator, this action of the device being diflerent from that of a thermostat. It will'be seen also that the arm 55 isso connected to the piston rod that the arm may be returned to itsnormal position by pushing the rod 29 to the right in Fig. 1 without inany way operating the dash pot device. Thus the operator may wish toreturn the parts to normal immediately after the motor starts andwithout waiting for the spring and dash pot device to operate and thisconnection permits him to do so. In Fig. 5 the, arm. is shown in fulllines in its raised position and in dotted lines the arm 55 has beenmoved downwardly to normal position without carrying the piston rod 45with it.

It will be understood further that the retainiug device 36, abovedescribed, while it is sutlicient to retain. the parts in any desiredposition as against the action of the carburetor spring 19 on the cam21, yet it is not sufficient to hold the rod. 29 against thereturn-to-normal action of the spring The by-pass 52 above described isparticularly related to the carburetor choke as will be seen in Figs. 1,2 and 5. In Fig. 1

port, 51.

in large quantities of raw: gasoline unless the: choke valve 16 is atonce opened. It will. be seen that in. Fig. 2 the piston 4-4 hasentirely over-traveled the port 53 and the bypass 52 therefore is (infull operation. This will permit the piston 44 to almost immediatelyretract as the'rod 29 is released by the operator when. the motorstarts. But

as soon as the piston has passed down oven the port 53 the bypass is cutoft and the oil can then pass only through the small Of course. it theoperator so dcsires, he can push the rod 29 towards the right in Fig. 1.immediately after the motor starts, and thus more quickly open the chokevalve 16 while still retaining the valve 18 on its seat by reason of thenearly'maximum. compression of its spring 19. After the operator hasleft the rod 29 in that position, he need be no further concerned withthe adjustment of the carburetor as. it will be automatically taken careof by the spring and dash pot device, the mixture varying parts of thecarburetor being returned to normal as the motor heats up. On the otherhand, the operator may if he desires, return the mixture varying part-spartly or wholly to normal position more rapidly than the spring anddash pot device will. return them, should he desire a leaner mixturethan the device is set to give. He cannot, however, leave the device inan intermediate position without having it auto: matically returned tonormal and thus he cannot run a hot motor on a rich mixture withoutconsciously holding the parts in abnormal position.

Referring to Fig. 9, a slightly modified form of spring and dash potdevice is found. The cylinder 40 and by-pass, 52, as well the piston 44and spring 47 arethe same. The piston rod 45, however, is drilled outand a rod 57 passes through the piston rod and connects by a cross bar58 with the valve 49 so that the latter maybe positively opened againstits spring 50. The upper end of the piston 1'0 45 has a slot 59 in whichthe end 56 of the arm 55 operates.

The slot,59 is slightly longer than the width of the head 56 and the rod57 extends into the slot in contact with the head 56. By this connectionit'w-ill be seen that the piston rod. 45 may be moved upwardly by thelit) I it) arm as in the other construction, but the arm 55 cannot bemoved downwardly without carrying the piston rod with it. To facilitatethe manual downward movement of the piston rod 45 the valve 49 is openedby the movement of the rod 57 and this is accomplished by the head 56sliding in the slot 59 and operating on the end of the rod 57. Thus inFig. 9 the arm 55 is in raised position in full lines and in dottedlines the arm 55 has been moved downwardly so that the valve 49 has beenopened thus permitting free passage of oil past the valve 59 and throughthe ports 48. Thus the operator may, as with the other construction,easily move the device in either direction and when he releases the rod29 the spring and dash pot device will act from then on to return theparts to normal, in accordance with the heat of the motor.

It will be understood that various forms of the invention other thanthose described above may be used without departing from the spirit orscope of the invention.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In'an internal combustion engine, the combination of a mixture devicetherefor, means for varying the mixture, a manually operated device tomove said varying means from normal position, automatic means forreturning said varying means to normal position upon manual releasethereof, and means governing the action of said automatic means.

2. In an internal combustion engine, the combination of a mixture devicetherefor, means for varying the mixture, a device to move said varyingmeans from normal position, automatic means for returning said varyingmeans to normal position, and means for slowing down the action of saidautomatic means.

3. In an internal combustion engine, the combination of a mixture devicetherefor, means for varying the mixture, a device to move said varyingmeans from normal posi-. tion, automatic means for returning saidvarying means to normal position, anda dash pot to retard the automaticreturn means.

4. In an internal combustion engine, the combination of a mixture devicetherefor, means for varying the mixture,'a manually operated device tomove said varying means from normal position, automatic means forreturning said varying means to normal position upon manual releasethereof, and means dependent upon the heat of the engine for governingthe action of said automatic means.

. 5. In an internal combustion engine, the combination of a mixturedevice therefor, means for varying the mixture, a device to move saidvarying means from normal position, automatic means for returning saidvarying means to normal position, and means acting sluggishly on a coldengine and less so on a warm engine, for retarding the automatic returnmeans.

6. In an internal combustion engine, the combination with the cylindersand a carburetor adapted to supply mixture thereto, said carburetorhaving means for changing the richness of the mixture, of a manuallyoperated device for moving said mixture changing means from normalposition, spring means forreturning said mixture changing means tonormal position, and retarding means for said spring means.

7. In an internal combustion engine, the combination with the cylindersand a carburetor adapted .to supply mixture thereto, said carburetorhaving means for changing the richness of the mixture, of a manuallyoperated device for moving said mixture changing means from normalposition, spring means for returning said mixture changing means tonormal position, and a dash pot adapted to retard the action of saidspring means.

8. In an internal combustion engine, the combination with the cylindersand a carburetor adapted to supply mixture thereto, said carburetorhaving means for changing the richness of the mixture, of a manuallyoperated device for moving said mixture changing means from normalposition, spring means for returning said mixture changing means tonormal position, and a dash pot mounted on the engine to receive heattherefrom, for retarding the return movement of the mixture changingmeans.

9.In an internal combustion engine, the combination with a carburetorhaving a selfreturning device for changing the mixture proportions,manually operated means for moving said device from normal posltion, a

device forfyieldingly retaining said means in any set position, a springadapted to overcome said retaining means and return'the mixture deviceto normal position, and a dash pot for retarding the operatlon of saidspring.

10. In an internal combustion engine, the combination with a carburetorhaving a self-returning device for changing the mixture proportions,manually operated means for moving said device from normal position, adevice for yieldingly retaining said means in any set position, a springadapted to overcome said retaining means and return the mixture deviceto normal position, and means affected by the heat of the engine, forretarding the action of said spring. a

11. In an internal combustion engine, the combination with a carburetorhaving a selfreturning device for changing the mixture I proportions,moving said device from normal position,

manually operated means for position, a dash pot connected to said meansa and adapted to retard the return action of device for yieldinglyretaining said means, said spring throughout all the range of the in anyset position, a spring adapted to overmovement of said device except thechoker come said retaining means and return the movement. mixture deviceto normal position, and an 15. In an internal combustion engine, the oildash pot mounted adjacent the engine combination with a carburetor, ofmeans for exhaust for retarding the action of said controlling thecarburetor comprising a spring. V --spring return device,- a cylinder, apiston in 12. In an\internal combustion engine, the the cylinder, and avalve adapted to open combinationiwith a carburetor having mixin onedirection .to permit free movement of ,ture controlling means, of amanually operthe piston.

ated device for moving said means from and means.

'ture controlling means, of a manually'opers a portion only of its fullstroke.

16. In an internal combustionengine, the to normal osltion, and a springdevice concombination W1tl1 a carburetor, of means, for

nected to-s aid manually operated means to controlling the carburetor.comprising a V yieldingly return it to normal position withspring returndevice, a cylinder, a piston in out aijtecting the manual return of;said the cylinder, a valve adapted to open in one direction to permitfree movementof the pis- 13. In an internal combustion engine,othe ton,and a by-pass to permit free movement combination with a carburetorhaving mixof thepiston in both directions throughout ateddevice formoving said means from and V 17 In 'an internal combustion engine, the

' to-normal position, and a spring and dash combination with acarburetor, of means for .pot device to return said means to normalposition.

controlling the carburetor comprising a cyl- J inder, a piston therein,,a piston-rod con- 14. In an internal combustion engine, the necterl tothe piston, a Valve, an arm for combination with a carburetor having amoving the piston, and a. connection from mixture controlling device anda choker, and the arm to the valve whereby the latter may means foroperating the mixture controlling be manually opened to permit freemovedevice throughout a given range and for ment-of the piston. closingthe choker near one end of the range yieldingly retaining said device innormal MI TON TIBBETTS:

I In testimony whereof I aflix my signa i of movement of sal'd'device,of a spring for turer I 1 i

